What's Needed for a Migraine Cost‐Of‐Illness Study in Aotearoa New Zealand: Review of Data Sources and Gaps

Cost of illness (COI) studies are used to quantify the economic burden of disease on health systems, employers and society, and identify where costs may be saved by improvements in disease management. Many migraine COI studies have been published internationally but none have included data from Aotearoa New Zealand (NZ), despite the known high prevalence and individual health burden of migraine. Adapting methods for data reviews developed at the University of Auckland, we reviewed known data sources to identify relevant NZ datasets containing information on migraine prevalence, direct and indirect costs from migraine, supplemented by searches of peer‐reviewed literature. Data sources were evaluated against pre‐defined criteria to assess quality. We found adequate data on migraine prevalence but limited to no data on migraine‐specific indirect costs (absenteeism or presenteeism, reduced employment or inability to work because of migraine). Data on direct costs were insufficient, due to poor or lack of diagnostic data in key areas such as primary care, pharmaceuticals, outpatients, laboratory or imaging tests. This review revealed significant data gaps that would need to be filled for a comprehensive and robust NZ migraine COI study or any ongoing research into migraine in NZ.